I've seen this before when installing from bad provisions of the USB stick. It seems that some sticks just don't want to work (I couldn't get it to work with one stick, but trying again with another stick worked better)

Try it with a different USB stick, or reformat and try your stick again. Failing that, I know DVD burns always work.

This is a problem with the Microsoft provided USB creation tool having bugs. It is better in RTM version but still has occasional problems.